Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS5885146 A
Publication typeGrant
Application numberUS 08/918,485
Publication dateMar 23, 1999
Filing dateAug 25, 1997
Priority dateDec 6, 1995
Fee statusLapsed
Publication number08918485, 918485, US 5885146 A, US 5885146A, US-A-5885146, US5885146 A, US5885146A
InventorsEric Cockburn
Original AssigneeBlack & Decker Inc.
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Oscillating hand tool
US 5885146 A
Abstract
A dual function powered oscillating hand tool comprises a driven unit having an electric motor and a first drive shaft; an eccentric bearing mounted on the first drive shaft with a radial offset e relative to the first drive shaft; a second drive shaft mounted on the eccentric bearing and terminating in a flange and a drive spigot; a sanding shoe; and a location hole positioned on the backing face of the sanding shoe for location of the second drive shaft and means to restrict the random orbit of the sanding shoe to a regular orbit. The drive spigot has a diameter d1 adjacent to the flange face and a maximum diameter d2 at its free end and the location hole has a diameter d3 at the backing face and a diameter d4 at the face adjacent to the working face of the shoe, and
d1 =d3 -c1 
d2 =d4 -c2 and
d2 =d3 -(2e-c1)
where c1 is the clearance between the drive spigot and the location hole at the flange face when the shoe is mounted on the second drive shaft and c2 is the clearance between the drive spigot and the location hole at the face of the location hole adjacent to the working face when the shoe is mounted on the second drive shaft.
Images(3)
Previous page
Next page
Claims(2)
I claim:
1. A dual function powered oscillating hand tool comprising
(i) a drive unit (2) having an electric motor and a first drive shaft (6);
(ii) an eccentric bearing (26) mounted on the first drive shaft (6) with a radial offset e relative to the first drive shaft (6);
(iii) a second drive shaft (24) mounted on the eccentric bearing (26) and terminating in a drive spigot (38);
(iv) a sanding shoe (22);
(v) a location hole (42) positioned on the backing face (46) of the sanding shoe (22) for location of the second drive shaft (24) and
(vi) means (40,44) to restrict the random orbit of the sanding shoe (22) to a regular orbit,
characterized in that the drive spigot (32) has a diameter d1 adjacent to the second end (36) of the second drive shaft (24) and a maximum diameter d2 at its free end (36) and the location hole (42) has a diameter d3 at the backing face (46) and a diameter d4 at the face adjacent to the outer face (50) of the shoe (22), and
d1 =d3 -c1 
d2 =d4 -c2 and
d2 =d3 (2e-c1)
where c.sub. is the clearance between the drive spigot (32) and the location hole (42) at the face of the location hole (42) adjacent to the backing face (46) when the shoe (22) is mounted on the second drive shaft (24) and
c2 is the clearance between the drive spigot (32) and the location hole (42) at the face of the location hole (42) adjacent to the outer face (50) when the shoe (22) is mounted on the second drive shaft (24).
2. A dual function powered oscillating hand tool according to claim 1 wherein the drive shaft (24) is formed with a section (28) having an end (36) which is closest to the drive spigot (32) characterized in that a flange (30) is located between the end (36) and the drive spigot (32).
Description

This application is a continuation of application Ser. No. 08/569,405, filed on Dec. 6, 1995, now abandoned.

The present invention relates to a powered oscillating hand tool, in particular an orbital sander, comprising a drive unit having an electric motor with a drive shaft to which a working head, for example a sanding shoe can be attached.

In sanders of the orbital type, with a shaped shoe, the drive system comprises an eccentric which is restrained so that the sander shoe cannot spin independently of the motor and it therefore describes a regular orbit. The shoes of such sanders are available in a range of shapes and such sanders are in general used for the removal of relatively small quantities of material, for example for detailed work or for finishing. By choice of a suitably shaped shoe, it is possible to access areas which are inaccessible with a random orbit sander.

The restraining mechanism by which the eccentric is restrained so that the sander shoe cannot spin independently of the motor and therefore describes a regular orbit, generally comprises a co-operating array of legs and spigots on the shoe and the sander body respectively. In order to avoid problems resulting from the system being out of balance, it is necessary for the location hole on the shoe, in which the drive shaft locates, to be centrally positioned on the shoe. This leads to difficulties in locating the location hole of the shoe on the second (eccentric) drive shaft at the same time as locating the corresponding legs and spigots. For the shaft to match the location hole on the shoe, it is necessary to deform the legs during this location. This has in practice meant that it has not been usual to provide orbital sanders with interchangeable, differently shaped shoes so that the user has generally had to purchase more than one orbital sander in order to have available a selection of differently shaped shoes.

Known sanders have hence been either of the orbital type as described above, with a fixed shoe or of the random orbit type in which a circular platen is driven by a drive system which comprises an eccentric bearing so that the platen can spin independently of the motor, and the platen describes a random orbit.

This has meant that when the user wished to have the ability to perform both coarse and detailed sanding operations, or to use differently shaped sanding shoes in order to access difficult areas it has been necessary for him to purchase two or more separate units of different types, or to purchase only one unit and suffer the disadvantages thereof.

It is a further disadvantage of the known sanders that the drive shaft to which the sander head is attachable, and the hole by which the head is mounted on the shaft are each of generally circular section, flatted on opposite faces to assist in retaining the head on the sander. This design is more expensive to manufacture than a circular section and has the further disadvantage that when the user locates the head on the shaft, it is necessary to align the opposed flats on the shaft and head correctly, in order to avoid damage to the head or the shaft.

It is an object of the present invention to provide a powered oscillating hand tool comprising a drive unit having an electric motor with a drive shaft to which a sander head can be attached, in which the attachment means by which the sander head is attachable to the drive shaft is particularly convenient.

The present invention therefore provides a powered oscillating hand tool comprising

(i) a drive unit having an electric motor and a first driveshaft;

(ii) an eccentric bearing mounted on the first drive shaft with a radial offset e relative to the first drive shaft;

(iii) a second drive shaft mounted on the eccentric bearing and terminating in a drive spigot;

(iv) a sanding shoe;

(v) a location hole positioned on the backing face of the sanding shoe for location of the second drive shaft and (vi) means to restrict the random orbit of the sanding shoe to a regular orbit,

characterised in that the drive spigot has a diameter d1 adjacent to the second end (36) of the second drive shaft and a maximum diameter d2 at its free end and the location hole has a diameter d3 at the backing face and a diameter d4 at the face adjacent to the working face of the shoe, and

d1 =d3 -c1 

d2 =d4 -c2 and

d2 =d3 -(2.sub. e-c1)

where c1 is the clearance between the drive spigot and the location hole at the face of the location hole adjacent to the backing face when the shoe is mounted on the second drive shaft and

c2 is the clearance between the drive spigot and the location hole at the face of the location hole adjacent to the working face when the shoe is mounted on the second drive shaft.

The attachment means according to the invention by which the sander head is attachable to the drive shaft is suitable for use in any powered oscillating hand tool which is provided with interchangeable heads and is particularly suitable for use in a dual function powered oscillating hand tool comprising

(i) a drive unit having an electric motor and a drive shaft;

(ii) a bearing mounted on the drive shaft and located radially eccentrically relative to the drive shaft;

(iii) a second drive shaft mounted in the eccentric bearing and

(iv) means for mounting a sanding platen or shoe on the second drive shaft characterised in that the sanding head may comprise a sanding platen for random orbit sanding or a sanding shoe for orbital sanding and in that the tool further comprises means selectively engageable to restrict the random orbit of the sanding shoe to a regular orbit, as described and claimed in our co-pending U.S. patent application Ser. No. 08/701,568 which is a continuation of U.S. application Ser. No. 08/503,109 now abandoned.

The invention thus provides a powered oscillating power tool which can easily be fitted with an orbital sander shoe or with an alternative sander head, such as a differently shaped sanding shoe or a random orbit sander head without requiring deformation of the restraining legs.

The invention will now be further described with reference to the accompanying drawings in which

FIG. 1 is a side view, partially in section, of the drive unit of a first embodiment of a hand tool according to the present invention, fitted with an orbital sander shoe;

FIG. 2 is an exploded view of the sanding shoe and drive shaft of FIG. 1 and

FIG. 3 is a section, on an enlarged scale, on a part of the tool according to FIGS. 1 and 2.

FIG. 4 is an enlarged portion of FIG. 1 showing a drive spigot located within a hole of a sanding shoe.

FIGS. 1 and 2 show a drive unit (2) including an electric motor (not shown) located in upper housing (4) and driving shaft (6). A fan (8) mounted on shaft (6) is arranged to draw air in from mouth (10) of lower housing (12) and direct it through extractor duct (14) to exhaust outlet (16). A screw (18) and washer (20) are used to secure a sanding shoe (22) to a second drive shaft (24) which is housed in the fan (8) by bearing (26) which is eccentrically located radially in respect to shaft (8).

The second drive shaft (24) comprises a first section (28), a flange (30) and a drive spigot (32). A first end (34) of the first section (28) is adapted for mounting in the bearing (26) and the flange (30) is mounted on the first section (28) at the second end (36) of the first section.

The second drive shaft (24) terminates in a drive spigot (32).

Two pairs of spigots (40) are arranged in an array within the lower housing (12), around the mouth (10) of the housing (12).

The sanding shoe (22) is provided with a location hole (42) for location of the drive spigot (32). Two pairs of hollow, tapering, flexible columns (44) made of rubber are arranged, in an array matching that of the housing spigots (40), on the backing face (46) of the shoe (22).

When the sanding shoe (22) is mounted on the second drive shaft (24), the tips (48) of the flexible columns (44) formed on the backing face (46) of the shoe (22) engage the housing spigots (40).

A perforated sandpaper sheet (not shown) may be attached to the outer face (50) of the shoe (22), for example by the use of hook-and-loop fabric such as that sold as VELCRO (RTM) glued to face (50). Holes (52) passing through the shoe (22) facilitate the removal of dust etc, from the sanding face through the shoe (22) to exhaust outlet (16) via the duct (14). An extractor hose (not shown) may be attached to the exhaust outlet (16).

As is shown in FIG. 3, the second drive shaft (24) comprises a first section (28), a flange (30) and a drive spigot (32). A first end (34) of the first section (28) is adapted for mounting in the bearing (26) and the flange (30) is mounted on the first section (28) at the second end (36) of the first section. The second drive shaft (24) terminates in the drive spigot (32).

The drive spigot (32) tapers from a diameter d1 at its face adjoining the flange (30) to a diameter d2 at its free end. The location hole (42) of the shoe (22) has a diameter d3 at the backing face (46) of the shoe (22), and a diameter d4 at the outer face (50) of the shoe (22).

The motor axis AM is offset from the axis AB of the eccentric bearing (26) by a radial eccentricity e.

As shown in FIG. 4, when the tool is assembled, with the shoe (22) mounted on the drive shaft (24), there is a clearance c1, at the level of the backing face of the shoe, between the drive spigot (32) and the location hole (42) and a clearance C2 at the level of the outer face.

In order to exchange a first shoe for an alternative shoe, the first shoe is removed and the alternative shoe is located an the second drive shaft.

The flexible columns (44) are located on the spigots (40) and the drive spigot (32) of the second drive shaft (24) is aligned sufficiently with the location hole (42) of the shoe (22) for the drive spigot (32) to be guided into the location hole (4) as the screw (18) is tightened and the shoe (22) secured to the second drive shaft (24).

While the powered oscillating hand tool according to the invention is particularly adapted for use with sanding heads such as orbital sanding shoes and random orbit sanding platens, it is of course within the scope of the invention to provide a tool to which further alternative oscillating heads can be attached.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2817192 *Jun 23, 1955Dec 24, 1957American Lincoln CorpGyratory and straight-line movement abrading machine
US3345784 *Dec 29, 1964Oct 10, 1967Rockwell Mfg CoOrbital finishing sander
US3436875 *Aug 5, 1966Apr 8, 1969Cheney Ralph RAbrasive disc holder
US3533193 *Nov 25, 1968Oct 13, 1970Singer CoDual motion pad sanders
US3742656 *Dec 18, 1968Jul 3, 1973R AmosCoupling devices
US3864784 *Mar 5, 1973Feb 11, 1975Electrolux AbSurface treating attachment device
US3943669 *May 8, 1974Mar 16, 1976Reinhold StroezelGyratory sander
US4137617 *Oct 17, 1977Feb 6, 1979Newmayer Rickey LCircular grater for cutting plastic
US4222297 *Mar 26, 1979Sep 16, 1980Northeastern, IncorporatedAdapter construction for arbor installation of tooling
US4468895 *Mar 28, 1983Sep 4, 1984Signorelli Gary JSurface grinder attachment
US4497141 *May 31, 1983Feb 5, 1985Sven JarbyMounting/operating a disc as a rotary tool on a disc drive
US4708041 *Aug 26, 1986Nov 24, 1987Granger Robert ALathe mounting apparatus
US4729194 *May 13, 1986Mar 8, 1988Festo KgBalanced orbital sander/grinder
US4907374 *Jul 22, 1988Mar 13, 1990Schaudt Maschinenbau GmbhWheelhead for grinding machines
US4943178 *May 8, 1986Jul 24, 1990Illinois Tool Works, Inc.Mounting structure for rotating bodies
US5061090 *May 31, 1990Oct 29, 1991Porter-Cable CorporationShaft and bearing assembly
US5468176 *Nov 1, 1993Nov 21, 1995Hilti AktiengesellschaftDisk-shaped tool bit for an angle grinder
DE2512438A1 *Mar 21, 1975Nov 13, 1975Vettiger Gmbh Maschinen U WerkSchnellverschluss zur loesbaren verbindung eines rotierenden werkzeuges, insbesondere eines schleifkoerpers mit einem tragkoerper
DE3714148A1 *Apr 28, 1987Nov 12, 1987Champion Spark Plug CoHaltevorrichtung fuer rotierende koerper
DE3724698A1 *Jul 25, 1987Feb 2, 1989Schaudt Maschinenbau GmbhSchleifkopf
DE4306829A1 *Mar 4, 1993Sep 8, 1994Lothar HolzapfelDish-shaped fastening anchor for detachably fastening a grinding ring (abrasive ring, ring wheel), connected thereto, to the end of a drive shaft
EP0541275A1 *Oct 23, 1992May 12, 1993Black & Decker Inc.Sanding apparatus
EP0559020A1 *Feb 19, 1993Sep 8, 1993Robert Bosch GmbhOrbit disc sander with limited disc speed
EP0596831A1 *Oct 21, 1993May 11, 1994HILTI AktiengesellschaftDisc-like tool for angle grinder
WO1988003076A1 *Oct 22, 1987May 5, 1988Guehring AutomationAbrasive disc arrangement for a high-speed grinding machine
WO1993017828A1 *Feb 24, 1993Sep 16, 1993Bosch Gmbh RobertEccentric disc grinder
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US6190245 *Aug 21, 1998Feb 20, 2001Dynabrade, IncQuarter pad sander
US6705931 *Jun 19, 2001Mar 16, 2004Skil Europe B.V.Plane sander with exchangeable part of sanding sole
US6758731Aug 10, 2001Jul 6, 2004One World Technologies LimitedOrbital sander
US6855040Feb 24, 2003Feb 15, 2005Hao Chien ChaoErgonomically friendly orbital sander construction
US7052383 *Sep 4, 2002May 30, 2006Robert Bosch GmbhManual orbital sander
US7270598May 11, 2004Sep 18, 2007Eastway Fair Company Ltd.Orbital sander
US7313838Nov 26, 2003Jan 1, 2008S.C. Johnson & Son, Inc.Powered cleaner/polisher
US7565712Sep 25, 2007Jul 28, 2009S.C. Johnson & Son, Inc.Powered cleaner/polisher
US7713110Sep 5, 2006May 11, 2010Dynabrade, Inc.Locking random orbital dual-action head assembly
US7736216Aug 20, 2008Jun 15, 2010Black & Decker Inc.Sander having removable platen
US8172642 *Aug 12, 2009May 8, 2012Black & Decker Inc.Multi-sander
US8398457May 7, 2012Mar 19, 2013Black & Decker Inc.Multi-sander
US8613644Mar 14, 2013Dec 24, 2013Black & Decker Inc.Multi-sander
US8821220 *Sep 26, 2013Sep 2, 2014Black & Decker Inc.Power tool with interchangeable tool head
US20100048101 *Aug 12, 2009Feb 25, 2010King Wade CMulti-sander
US20140024301 *Sep 26, 2013Jan 23, 2014Black & Decker Inc.Power tool with interchangeable tool head
EP1156575A1 *Dec 20, 2000Nov 21, 2001A & A CorporationEccentric revolving drive unit
EP2156925A2Aug 20, 2009Feb 24, 2010BLACK & DECKER INC.Sander
WO2001094073A1 *May 11, 2001Dec 13, 2001Huber Paul WilliamErgonomically friendly orbital sander construction
Classifications
U.S. Classification451/357, 451/344, 451/490
International ClassificationB24B23/04
Cooperative ClassificationB24B23/04
European ClassificationB24B23/04
Legal Events
DateCodeEventDescription
May 10, 2011FPExpired due to failure to pay maintenance fee
Effective date: 20110323
Mar 23, 2011LAPSLapse for failure to pay maintenance fees
Oct 25, 2010REMIMaintenance fee reminder mailed
Jul 7, 2006FPAYFee payment
Year of fee payment: 8
Jul 1, 2002FPAYFee payment
Year of fee payment: 4